1. Field of the Invention
The present invention relates to a sprayable aerosol composition which is a liquid in the aerosol container and forms a gel upon application to the skin.
2. Prior Art
The preparation of aqueous gels employing as gelling agents polyoxyethylene-polyoxypropylene block copolymers is well known to those skilled in the art and is taught in several patents including U.S. Pat. No. 3,740,421. Such gels may be advantageously employed in the preparation of topically applicable cosmetic and pharmaceutical compositions. It is also known in the art to apply such compositions by the use of aerosol-type containers. However, filling an aerosol container with a gel presents problems.
U.S. Pat. No. 3,751,562, issued Aug. 7, 1973, to Nichols, discloses an aerosol gel formulation employing an oxyethylated fatty alcohol, mineral oil, iodine and water.
U.S. Pat. No. 4,293,542, issued Oct. 6, 1981, to Lang et al, discloses aerosol formulation which can be an aqueous gel containing oxyethylated fatty alcohols and a gel-forming agent and, as an essential component, a pyridine derivative.
British Pat. No. 1,096,357 discloses an aerosol gel comprising a partial fatty acid soap of a polyvalent metal hydroxide and a nonpolar oil along with propellants.
In U.S. Pat. No. 3,476,853, a sprayable composition for use as a dressing, including a film-forming material, an opacifying material, at least one medicament, a solvent and a gaseous propellant, is disclosed. The fluid dressing or bandage is applied by spraying the fluid dressing from a closed pressure-resistant container by the expansion of a normally gaseous propellant in liquid state. The patent discloses a means for applying a protective opaque film which is immediately dry to the touch when applied from a distance of 4 to 6 inches. This provides a simulated bandage.
British Pat. No. 1,444,334 discloses an aerosol gel composition which may be employed as a shaving cream composition and which contains as a gelling agent a polyoxypropylene-polyoxyethylene block copolymer. The composition also includes a water-soluble soap. This patent is concerned with the problem of expelling a gel from an aerosol container and particularly avoiding cavitation around the dip tube as can be seen from column 2 thereof. Accordingly, the compressed gas or liquified gaseous propellant is required to be substantially insoluble in the gel so that it can act in the manner of a piston to force the gel from the container without cavitation.
Copending U.S. patent application Ser. No. 513,439 discloses an aerosol gel burn treatment composition which is a liquid in the aerosol can and forms a gel upon application to the skin. This application requires as an essential component a volatile solvent in addition to the propellant.